Reorganized environment-related functions.

lib/env.ml~

@@ -0,0 +1,28 @@
+let env_set_local env s v =
+  match env with
+  | [] -> ()
+  | e1 :: _ -> Hashtbl.replace e1 s v
+
+let rec env_update env s v =
+  match env with
+  | [] -> ()
+  | e1 :: erest ->
+     match Hashtbl.find_opt e1 s with
+     | None -> env_update erest s v
+     | Some _ -> Hashtbl.replace e1 s v
+
+let env_new_lexical env = 
+  let h = Hashtbl.create 16 in
+  h :: env
+
+let rec env_root (env : environment) =
+  match env with
+  | [] -> raise (Invalid_argument "Empty environment passed to env_root!")
+  | e :: [] -> e
+  | _ :: t -> env_root t
+
+let env_set_global env s v =
+  Hashtbl.replace (env_root env) s v
+
+let env_copy env =
+  List.map Hashtbl.copy env